Why do they call flight data recorders a "black box" if it's orange in color?

Just curious about this since I've seen several images of black boxes but they all come in orange colors, and not black. I can understand orange being used to help brightly identify the box , but then why call it a "black" box?

$\begingroup$I have always thought of it as a (western) cultural influence. Many people believe these boxes are read only after a fiery crash, i.e. with fatalities. Death is associated with black in western cultures, hence the name.$\endgroup$
– oriqueFeb 15 '16 at 7:11

$\begingroup$+1 for the update. I suspect that may be the real answer - in electronics it's a common term and from an avionics point of view this is a "don't care" box. The avionics will work fine without it.$\endgroup$
– Dan PichelmanMar 25 '14 at 21:11

$\begingroup$Another possible reason can be"Just like black hole which contains all light this is black box which contain all the necessary flight data". This flight reveal every important information of flight as if whoever decodes it can identify flight trajectory, surface position, engine rpm, warnings etc.$\endgroup$
– ToUsIfFeb 5 '15 at 7:45

1

$\begingroup$I think this is the correct answer, but the point is not that the internal workings are not of interest, but that apart from the actual data inputs they are totally isolated and separate from the rest of the system so that the do not fail when the rest of the system fails. That lack of dependencies is what makes the internals "not of interest" both for FDR and for "black boxes" in general. And what allows black boxes to serve their function after the rest of the plane has broken to small pieces scattered over several square miles of ocean.$\endgroup$
– Ville NiemiFeb 14 '16 at 11:50

The Wikipedia article on Flight recorder offers a possible explanation for the origin of the term:

... they were essentially photograph-based flight recorders since the record was made on a scrolling photographic film. The latent image was made by a thin ray of light deviated by a mirror tilted according to the magnitude of the data to record (altitude, speed, etc.). Since the inside of the recorder was pitch black, this may be the origin of the "black box" name, often used as a synonym for a flight recorder.

Interestingly, the Wikipedia article on Black box claims that the term entered the English language around 1945, which is a few years after the first flight data recorder was built.

The correct answer seems to be, "Nobody knows for sure" but here's some data.

The earliest citation in the Oxford English Dictionary for the phrase "black box" referring specifically to a flight data recorder isn't until 1964, from the UK Daily Telegraph: "The flight recorder is an indestructible 'black box' which automatically records the key functions in the aircraft..."

There are earlier uses of the phrase, with different meanings. Since 1932, it has been used to mean a device whose internal workings are unclear but which is specified by its inputs and outputs; since 1945, it has been used in the Royal Air Force to refer to various navigational devices which, according to Wikipedia sometimes were housed in literal boxes that were black.

My interpretation/thoughts/speculation/whatever word you want to use:

The use of quote marks in the Daily Telegraph seems significant. First, it suggests that we're not talking about a literal box which is black and you might imagine they'd say something like " 'black box' (which is now actually orange)" if they were formally literal black boxes. Second, "a 'black box' " suggests that the FDR might be just one of several devices on a plane that could be described as "black boxes". Unfortunately, that seems consistent with both of the other given definitions: you could perfectly well imagine it being RAF-style slang for "This electronic box of tricks does navigation, this one holds the autopilot and this one records flight data" or the input-output version of "I don't know exactly how the autopilot works, but I know what it does; ditto the navigation system; ditto the data recorder."

$\begingroup$Regarding first use to refer to a flight data recorder, Wikipedia says: "The first use of the term 'black box' in reference to flight data recorders and cockpit voice recorders was by Mr E. Newton of the AAIB at a meeting of the Aeronautical Research Council in August 1958.", referring to this document, p.16. Specifically, on August 27 1958, Newton "made the earliest recorded description of the device as a ‘black box’".$\endgroup$
– user2168Jul 24 '14 at 16:22

The adjective "black" in "black box" means "opaque". Engineering also uses the phrase "black box testing", which means tests that are done without access to system internals.

Similarly, "white box" means transparent, in which internal signals may be recorded or manipulated.

A black box recorder is presumably recording pilot actions on the system as well as the state shown to the pilot on the instruments, but none of the avionics internal variables. I doubt any modern FDR would be designed this way, however, since without the internal variables diagnosis of failure could be very difficult.

$\begingroup$Actually, I think it's the recorder that is a "black box", rather than the signals being recorded. You don't know how it records the data. You don't normally care how it records the data. In fact you normally don't know or care what data it records. As far as the pilot is concerned, it's just a mysterious piece of avionics which gets tested periodically, gets ignored most of the time, and hopefully will never actually be used.$\endgroup$
– keshlamMar 25 '14 at 23:02

$\begingroup$When you say that a black box recorder "presumably" does certain things and that you "doubt" that one would do other things, it suggests rather strongly that you're speculating. It also sounds like you're not quite sure what a black box does.$\endgroup$
– David RicherbyMar 25 '14 at 23:53

$\begingroup$@David: This question asks about terminology, I don't think one needs to know about every model of FDR in use. Do you mean to imply that there aren't variations between FDRs in use in different aircraft, different fleets, different countries? (Of course the pilot conversations, actions, and displayed data are recorded, but these are only the minimum data set) I'm not trying to provide the ultimate authoritative answer here, just provide additional context which I feel believe to be helpful.$\endgroup$
– Ben VoigtMar 25 '14 at 23:57

$\begingroup$@keshlam: That's a good point, although I would say it's not that pilots don't care, but that the recorder functions best when it is opaque and cannot be manipulated by the crew.$\endgroup$
– Ben VoigtMar 26 '14 at 0:00

$\begingroup$Also a good point. Tamper resistance is a Good Thing if you want to catch and critique the "oops" moments as well as the outright disasters.$\endgroup$
– keshlamMar 26 '14 at 2:46

One other theory I've heard (but been unable to verify) about the origin of the term "black box" in popular literature is that the boxes when found often tend to be black.
Not as a result of being painted black, but as a result of having been inside a burning aircraft wreck, covered in soot and burnt paint.

Whether that's the (or even one of the) reason for the term is probably lost in the mists of time. I seriously doubt it's ever been written down by the people inventing the term (newspaper journalists most likely) what their reasoning was.

$\begingroup$Well at least my source makes a lot of sense rather than a lot of the assumptions above that are based on nothing more than someone's personal view$\endgroup$
– Les EslingJul 24 '14 at 7:47

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